Polymers containing units of carbon monoxide and one or more ethylenically unsaturated compounds have been known for some time. Brubaker et al, U.S. Pat. No. 2,495,286, produced such polymers in the presence of free radical initiators such as peroxy compounds. Linear alternating polymers of carbon monoxide and ethylenically unsaturated hydrocarbons are disclosed by Nozaki who employed catalysts comprising arylphosphine complexes of palladium moieties in conjunction with certain inert solvents. See, for example, U.S. Pat. No. 3,694,412. Nozaki also disclosed the use of unsaturated compounds other than hydrocarbons, e.g., vinyl acetate. In published European Patent Application No. 121,965 there is disclosed, in the production of linear alternating polymers, the use of catalyst compositions formed from a compound of palladium, the anion of a strong non-hydrohalogenic acid and a bidentate ligand of phosphorus. Published European Patent Application No. 251373 discloses the use of non-hydrocarbyl unsaturated compounds in which the functional group is directly attached to a carbon atom of the ethylenic unsaturation, e.g., vinyl acetate or methyl acrylate. Nozaki, U.S. Pat. No. 3,835,123, discloses the use of doubly unsaturated compounds such as vinyl crotonate or vinyl hexanoate. It is not clear which of the unsaturated linkages serves as the site for the polymerization. In Drent, U.S. Pat. No. 4,841,020, the production of linear alternating polymers of carbon monoxide and non-hydrocarbyl ethylenically unsaturated compounds is disclosed in which at least one carbon atom separates the ethylenic unsaturation and the functional substitution. Such polymers are produced in the presence of a catalyst composition formed from, in part, a tetraaryl diphosphine. The use of other types of phosphine in the formation of catalyst compositions for linear alternating polymer production is known, for example, from published European Patent Application 376,364 which employs tetraalkyl diphosphines but the resulting catalyst compositions are not used to produce linear alternating polymers containing moieties of functionally-substituted ethylenically unsaturated compounds.
The linear alternating polymers, now known as polyketones or polyketone polymers, are characterized by a plurality of carbonyl groups occurring in the polymeric chain. Broadly speaking, the polyketones are thermoplastic and have established utility in the production of shaped articles such as containers for food and drink by techniques conventional for thermoplastic polymers. In addition, the polyketones are chemically modified by reaction at the carbonyl groups. For example, catalytic reduction in the presence of ammonia or hydrogen sulfide leads to production of polyamines or polythiols, respectively. Greater opportunities for chemical modification of the polymers exist when one or more of the ethylenically unsaturated monomers of the linear alternating polymers contains functional substitution. For example, hydrolysis of a linear alternating polymer produced from a monomer having ester functional groups would lead to polymers with acid or alcohol moieties pendant from the polymer chain.
In the process of U.S. Pat. No. 4,841,020 the use of tetraaryl diphosphines as catalyst composition precursors results in the production of functionality-substituted linear alternating polymers which can be chemically modified. The polymers of U.S. Pat. No. 4,841,020 have a disadvantage, however, in that they are of relatively low molecular weight which tends to limit their use in some applications. It would be of advantage to provide a process for the production of linear alternating polymers of carbon monoxide and functionally-substituted ethylenically unsaturated compounds which retain the opportunity for chemical modification of the polymer but are of a higher molecular weight.